Quantitative Determination of Fluorinated Alkyl Substances by Large-Volume-Injection Liquid Chromatography Tandem Mass SpectrometryCharacterization of Municipal Wastewaters

Abstract

A quantitative method was developed for the determination of fluorinated alkyl substances in municipal wastewater influents and effluents. The method consisted of centrifugation followed by large-volume injection (500 microL) of the supernatant onto a liquid chromatograph with a reverse-phase column and detection by electrospray ionization and tandem mass spectrometry. The fluorinated analytes studied include perfluoroalkyl sulfonates, fluorotelomer sulfonates, perfluorocarboxylates, and select fluorinated alkyl sulfonamides. Recoveries of the fluorinated analytes from wastewater treatment plant (WWTP) raw influents and final effluent were in the ranges of 82-100% and 86-100%, respectively. The lower limit of quantitation was 0.5 ng/L depending on the analyte. The method was applied to flow-proportional composites of raw influent and final effluent collected over a 24 h period from 10 WWTPs nationwide. Fluorinated alkyl substances were observed in wastewater at all treatment plants, and each plant exhibited unique distributions of fluorinated alkyl substances despite similarities in treatment processes. In 9 out of the 10 plants sampled, at least one class of fluorinated alkyl substances exhibited increased concentrations in the effluent as compared to the influent concentrations. In some instances, decreases in certain fluorinated analyte concentrations were observed and attributed to sorption to sludge.

Evaluation of perfluorinated compounds in seven wastewater treatment plants in Beijing urban areas

“…There were little variations of the concentrations among the seven WWTPs for both compounds. The PFOS concentration was at similar levels as reported in studies from Schultz et al [17,18], Sinclair and Kannan [19] but lower than those from Murakami et al and Becker et al [22,28].…”

“…As PFOS can be easily adsorbed to the solid due to its hydrophobic characteristic, the decrease may be due to the adsorption and removal by the sludge. The reduction of PFOS in effluents has also been observed in WWTPs by Schultz et al [17]. The existence of potential sources of PFCs in the form of precursor compounds or other telomers within the wastewater treatment, such as POSF (perfluorooctane sulfonyfluoride)-based perfluorochemicals and fluorotelomer alcohols (FTOHs), has been reported in several earlier studies [20,30,31].…”

“…These compounds have been widely used as surfactants and in the process of a variety of products from the 1950s and some of them are still in use today. During the activated sludge treatment process, these compounds were biodegraded, becoming a likely source of PFCs in the effluent [17][18][19]. Particularly, perfluorocarboxylates have been demonstrated to be the end biodegradation products from FTOHs in activated sludge [21,32].…”

“…Murakami et al also proposed that most PFCs in surface waters during dry weather are derived from wastewater and manufacturing effluents [16]. The occurrence of PFC contamination in wastewater treatment plants (WWTPs) has been observed in several countries [17][18][19], although the distribution and fate of PFCs during the wastewater treatment process remain vague. The occurrence of PFCs in sludge from several WWTPs suggests a portion of PFCs in wastewater may transfer to the solid during the treatment process.…”

Congener specific organic carbon normalized soil and sediment-water partitioning coefficients for the C1 through C8 perfluoroalkyl carboxylic and sulfonic acids

“…PFAs have also been studied in municipal wastewater treatment plants (WWTPs) [7,33,37,42,43,[48][49][50]64,69,80,[136][137][138][139][140][141] where sorption of contaminants to organic matter and settling with particulates in grit chambers, trickling filters, rotating biological contactors, and primary/secondary clarifiers, as well as sorption to activation carbon if this polishing step is present, is a major removal process from the final effluent stream. Although it has been previously noted that a means of estimating K oc values for the C 1 through C 8 PFAs would be valuable in better understanding PFA profiles within WWTPs, [137] the potential range of PFA precursors that are subject to biological and physicochemical degradation into PFAs (e.g., perfluoroalkyl sulfonamides, fluorotelomers, etc.)…”